High Speed Schottky Rectifier
AssigneesYutechnix, Inc., Champion Microelectronic Corp.
InventorsHo-Yuan Yu, Haiping Dun, Hung-Chen Lin
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Abstract
Apparatus, methods and other embodiments associated with a high speed and high breakdown voltage Schottky rectifier are disclosed. In one embodiment, the Schottky rectifier has three layers of N-type semiconductor, a first layer of highly doped N-type substrate at the bottom, a second layer of lightly doped epitaxial N-type material above the first layer, and a third layer of very low doping concentration N-type material created by converting the top shallow portion of the second layer without turning into P-type. The Schottky device further includes an enclosed deep trench structure close to the bottom of the second layer and can sustain high reverse bias voltage up to 2,000 volt.
Claims18
A Schottky device, comprising:
- a first layer of a semiconductor material of a first conductivity type;
- a second layer of the semiconductor material deposed on top of the first layer, wherein the second layer is an epitaxial layer with doping concentration lower than the doping concentration of the first layer;
- a third layer of the semiconductor material extending from top surface of the second layer by implant and being a shallow portion of the second layer, wherein the third layer in ring shape reduces the concentration of top shallow portion of the second layer to a degree not turning the third layer into a second conductivity type;
- and
- a Schottky contact in contact with top surface of the third layer, wherein the third layer is a single crystal;
- wherein the first conductivity type and the second conductivity type have opposite polarity;
- wherein the first layer, second layer and the third layer have same conductivity type.
(canceled)
A Schottky device, comprising:
- a first layer of a semiconductor material of a first conductivity type;
- a second layer of the semiconductor material deposed on top of the first layer, wherein the second layer is an epitaxial layer with doping concentration lower than the doping concentration of the first layer;
- a third layer of the semiconductor material in ring shape deposed on top of the second layer, wherein the third layer is a shallow epitaxial layer with doping concentration lower than the doping concentration of the second layer, and depth of the third layer is around 1/20 to 1/60 ratio of the depth of the second layer;
- and
- a Schottky contact in contact with top surface of the third layer, wherein the third layer is a single crystal;
- wherein the first layer, second layer and the third layer have same conductivity type.
A method for manufacturing a Schottky device, comprising:
- forming a first layer of a semiconductor material of a first conductivity type;
- forming a second layer of the semiconductor material on top of the first layer, wherein the second layer is an epitaxial layer with doping concentration lower than the doping concentration of the first layer;
- forming a third layer of the semiconductor material by implant, the third layer extending from top surface and being a shallow portion of the second layer, wherein the third layer reduces concentration of the top shallow portion of the second layer to a degree not turning the third layer into a second conductivity type;
- and
- forming a metal layer above the third layer to create a Schottky contact between the metal layer and the third layer;
- wherein the third layer is a single crystal;
- wherein the first conductivity type and the second conductivity type have opposite polarity;
- wherein the first layer, second layer and the third layer have same conductivity type.
A method for manufacturing a Schottky device, comprising:
- forming a first layer of a semiconductor material of a first conductivity type;
- forming a second layer of the semiconductor material on top of the first layer, wherein the second layer is an epitaxial layer with doping concentration lower than the doping concentration of the first layer;
- forming a third layer of the semiconductor material on top of the second layer, wherein the third layer is a shallow epitaxial layer with doping concentration lower than the doping concentration of the second layer, and depth of the third layer is around 1/20 to 1/60 ratio of the depth of the second layer;
- and
- forming a metal layer above the third layer to create a Schottky contact between the metal layer and the third layer;
- wherein the third layer is a single crystal;
- wherein the first layer, second layer and the third layer have same conductivity type.
Dependencies are inferred from the claim text.